clutch chatter/jump help

[josh4892]

when i let out of 1st gear, the clutch chatters/jumps

i got a 70 bronco, with a 4 inch lift kit

put shims in to try to fix it

changed clutch and pressure plate

and it only does it in 2 wheel drive, when i drive in 4 wheel drive it runs smooth

i need help with this, so if anyone has experienced this i would love some help

 

[S_bolt19]

It has nothing to do with your clutch. It is called axle wrap and can be cause by a number of things, but worn out leaf springs are typically the culprit. What happens is that when you hit the gas from a take off, your pinon gear climbs the ring gear inside the rear pumpkin. My first question is how old are your rear leafs & is your lift done with blocks, add-a-leaf or true lift springs? Lets start there and see where that takes us.

 

[josh4892]

the lift is done with add a leafs, but i looked under the truck while a friend was taking off and it didnt visably wrap up

It has nothing to do with your clutch. It is called axle wrap and can be cause by a number of things, but worn out leaf springs are typically the culprit. What happens is that when you hit the gas from a take off, your pinon gear climbs the ring gear inside the rear pumpkin. My first question is how old are your rear leafs & is your lift done with blocks, add-a-leaf or true lift springs? Lets start there and see where that takes us.

 

[S_bolt19]

You're not going to actually see it "wrap". What you will see is the pumpkin rotate downwards slightly. What this does is flexes those springs into an "S" shape. Now, like I said, you won't physically see your springs turn into that "s" shape and you wont see the axle wrap up like you would think. It doesn't take much movement at all to make that shutter. Did you put the add-a-leaf in or did a previous owner do it? If you did it, how long ago & how old are your springs to begin with? I had a set of springs that were 10 years old that caused the same problem and when I replaced them, it stopped.

 

[Bully Bob]

Hi Josh...,

When you say "changed clutch and pressure plate" are we talking "new" & re-surfaced ..or swapped in a used clutch, P/plate & T/O bearing...? /emoticons/[email protected] 2x" width="20" height="20" />

Shims....?? Where exactly.., & to fix what..?

Did this just start or has it been an on-going prob..?

Can we assume you checked/tested all the trannie/trnsfr. bearings, output shafts/yokes, U-joints, & pinion bearing, etc.

While the gear boxes were out..?

"...clutch chatters/jumps" Is this audible...or just a seat-o-the-pants feeling..?

Oh.., & It would help a bunch.., if you offered up what we're work'n on here....!!

Eng. trannie Trans., etc.. And any other mods. (fill in your sig. page as well.)

This would be a good thing....

B

 

[josh4892]

First, it is Brand new clutch, brand new pressure plate, brand new flyweel and pinion bearing.

and we just threw some shims on the rear axel seing if it was the angle of the axle causing the chatter

and this has been a 14 year prob, long time, since my dad has had it.

and we checked all the trannie/trnsfr. bearings, output shafts/yokes, U-joints, & pinion bearing, etc

and if it means anything when we put it in 4x4 low it is not noticeable very much

and this is a kick in the pants, a rattle in the teeth, down to your fingernails.......it feels like its jumping out from under you..

Hi Josh...,When you say "changed clutch and pressure plate" are we talking "new" & re-surfaced ..or swapped in a used clutch, P/plate & T/O bearing...? /emoticons/[email protected] 2x" width="20" height="20" />

Shims....?? Where exactly.., & to fix what..?

Did this just start or has it been an on-going prob..?

Can we assume you checked/tested all the trannie/trnsfr. bearings, output shafts/yokes, U-joints, & pinion bearing, etc.

While the gear boxes were out..?

"...clutch chatters/jumps" Is this audible...or just a seat-o-the-pants feeling..?

Oh.., & It would help a bunch.., if you offered up what we're work'n on here....!!

Eng. trannie Trans., etc.. And any other mods. (fill in your sig. page as well.)

This would be a good thing....

B

 

[josh4892]

a previous owner did the add a leaf in the back and front, with the springs being atleast 14 years old....so maybe we'll go for that next.

now i have pictures too, in my gallery showing all the springs and stuff visibly,

and if you do look at what i already have on there, where do you reccomend i get new ones? and should i get new ones for both front and back?

thanks, sorry its been a long time, i just got back to my bronc

You're not going to actually see it "wrap". What you will see is the pumpkin rotate downwards slightly. What this does is flexes those springs into an "S" shape. Now, like I said, you won't physically see your springs turn into that "s" shape and you wont see the axle wrap up like you would think. It doesn't take much movement at all to make that shutter. Did you put the add-a-leaf in or did a previous owner do it? If you did it, how long ago & how old are your springs to begin with? I had a set of springs that were 10 years old that caused the same problem and when I replaced them, it stopped.

 

[Bully Bob]

"this is a kick in the pants, a rattle in the teeth, down to your fingernails.......it feels like its jumping out from under you.."

What you're describing here.., I doubt, has anything to do with your suspension. I don't see any problems from the pics.

Except those look like 5pac rear leafs W/maybe an add-a-leaf...that's prob. pretty stiff..?

I would now be suspicious of the motor mounts...they can be seperated & not noticeable.

------- Does it shutter in reverse as well...? ---------

You can test them by placing a slab of wood under the pan & slooooly jack it up & watch the mounts.

It only takes a slight movement to see a visible crack.

--------If they're good & you go too high., it could ruin them. (Split)

The rear mounts attach to the T-case...something could be loose or broken there as well. Rubber pads gone bolt snapped, etc.

----------OR-----------

There's something still amiss in the clutch set-up .... :wacko:

 

[josh4892]

"Except those look like 5pac rear leafs W/maybe an add-a-leaf...that's prob. pretty stiff..?"

sooo, could it still possibly be the springs? would stiffness cause this?

"You can test them by placing a slab of wood under the pan & slooooly jack it up & watch the mounts."

ill try this tomorrow if i have time, and get back, but most of the stuff that is being mentioned here we have done a few times already.....especially with the clutch setup lol

and no, it doesnt do it in reverse, only in 1st and second

 

[Bully Bob]

"sooo, could it still possibly be the springs? would stiffness cause this?"

Usually., the stiffer the rear suspension., the less likely any axle wrap...assuming the U-bolts., spring hangars & bushings are all good.

"and no, it doesnt do it in reverse, only in 1st and second"

That makes me even more suspicious of a motor mount....prob. driver side.

(If memory serves., if it lurches in reverse.., it's a pass. side mount.)

------------ADDED-----------

Another quick test would be to remove the rear dr. shaft completely.

Try forward & reverse in 4 wheel dr. If it now 'jumps' in reverse...a bad mount is likely.

Lastly.., does it have a TAD.. (traction adding device) in the rear end..?

Rarely is this a prob. but not impossible.

 

[MUZZALL]

Is it chattering when the clutch is engaging or after it engages?

What brand and style of clutch did you put in?

 

[Bully Bob]

BTW.,

In your signature you said;

"...someone said it is "bored, stroked, and camed, help me out with what this means haha"

This means;

cylinder bored = more cubic inches

..........stroked = more piston travel=more cubic inches & a bit more torque.

...........camed = altering the duration, etc. of the valve opening & closing.

Usually done;

to move the horsepower up higher on the power curve. (as in peak HP at higher RPM's)

This is not necessary in a 4x4 as "wheel'n" is usually done at low RPM's

---Your eng. is likely to be closer to 300 cu.in. now.

One other thing..,

The front springs are fine..., but may be a bit stiff...as they are not progressive., as are the newer lift kit coils.

 

[josh4892]

it does it while it is engaging, and it is just a stock clutch from autozone

Is it chattering when the clutch is engaging or after it engages?
What brand and style of clutch did you put in?

 

[MUZZALL]

Have you driven the bronco much? You may just need to get used to the clutch. When I haven't driven my bronco for a while I get some clutch chatter to. When my wife drives, I think things are going to fall off the bronco at about every stop. I've found that every rig has a different feel and "sweet spot" to its clutch. There is a big difference between my Bronco (peppy 289 / 3spd) and my F-250 ( diesel / 5spd).

 

[josh4892]

i think i found out what was wrong, we took the rear axle apart, and it had 25 years of dirt, sand, and water in it, everything inside it is getting replaced since it was all torn up, but i should find out soon if that is what it was, and if it isnt....i will probably go to the leaf springs next....

thanks for all your help, lets hope this fixes the problem and i get it back on the road..

 

[Bully Bob]

If there's a "TAD" in there (posi, etc.) as I suggested...,

(----you didn't say ---)

Then it's likely you'll be good to go...! All that crap in there would give a "TAD" fits..!

 

[josh4892]

I THINK MY BRONCO IS FINALLY FIXED!!!

after trying avery little thing known to man, and i mean everything, to fix the "bucking bronco syndrome",

all i needed was a heavy duty racing clutch, we put one in, i think it was like $500, it seems to have cured the problem, lets hope it stays that way

 

[Bully Bob]

Outstanding..!!

And thanks for the "feedback" ----- that really helps others.

For example., there's very few parts worth buying fr. China auto parts....